Field of the Invention
The present invention is directed to valves for water systems, and, in particular, to valve systems for maintaining pressure and headloss in pipelines.
Description of Related Art
Water systems generally require valves that are capable of maintaining a pressure in the pipelines. This is typically achieved by using a pressure sensor linked to a control valve, or by using the internal fluid pressure in the pipeline to enter a series of pressure balanced diaphragms within the valve. While these approaches are able to maintain pressure in the pipelines, they have various drawbacks. For instance, the control valve linked to the pressure sensor requires an external power source to actuate the valve. Further, the use of internal fluid pressure to directly and intimately effect operation will cause the system to become inoperable if the liquid is dirty or creates deposits that clog the passageways and diaphragms. Springs could also be used; however, springs significantly increase the pressure for operating the valve as the springs become compressed and exert more force. Thus, it is desirable to provide a valve for maintaining pressure and headloss in a pipeline that does not have the drawbacks associated with known devices and methods.